Method of applying waste rubber materials for construction of golf courses and athletic fields

ABSTRACT

A method for utilizing waste rubber materials for construction of turf areas such as golf courses or athletic fields is disclosed. The method involves implementing waste rubber materials as a drainage layer to provide the following benefits: capability of adsorbing contaminants, insulation, and a lightweight construction backfill material. Also, the method involves the use of waste rubber materials as a supporting layer for athletic fields for the resiliency and shock absorption. Secondly, a method for utilizing waste rubber materials for filtration of runoff from turf or vegetated areas is disclosed. The method involves implementing waste rubber materials as a filter medium for adsorption of contaminants from runoff before entering detention ponds, wetlands, or other water bodies.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] none

FEDERAL RESEARCH STATEMENT

[0002] The inventors did not receive any funding from federal or stateagencies for this invention.

BACKGROUND OF INVENTION

[0003] Many industrialized nations battle with an increasing number ofstockpiled tires, a problem that introduces serious environmental,aesthetic, and health risks such as providing a breeding site formosquitoes. The environmental impact is extremely evident whenstockpiled tires catch fire, a situation that is difficult to extinguishand releases harmful gases into the atmosphere.

[0004] The Environmental Protection Agency reported 31% of discardedtires were landfilled, stockpiled, or illegally dumped in the UnitedStates in 1995 totaling nearly 78.5 million tires (EPA, 1996). Onlythree years later, the numbers increased to 34% discarded in the samemanner accounting for 92.5 million tires (National Rubber Association,1998). To further amplify the problem, by 1998, 48 states had scrap tireregulations, 33 states had banned whole tires from landfills, and 12states had prohibited all scrap tires from landfills. In the same year,approximately 500 million tires were in stockpiles.

[0005] In recent years, crumb rubber has become a popular material forcivil engineering applications such as road construction, and theturfgrass industry has found it useful as topdressing for increasedtraffic tolerance and compaction resistance in turfgrass (Jaitire Inc.,2000). In two field studies, one by the Minnesota Pollution ControlAgency (1990) and the other by Humphrey and Katz (1995), tire chipsplaced underground were found to have no significant effect ongroundwater quality despite the fact that some chemicals potentiallyleach from shredded tires. Their results have been supported by similarresearch (Scheels and Park, 1995) concluding that these applications areenvironmentally safe and beneficial for reducing tire stockpiles. Scraptires have been used in asphalt pavement for the following reasons:longevity of pavement, reduced noise, reduced freeze-thaw damage, etc.Tire chips can significantly reduce the potential for freeze-thawdamage. Scheels and Park (1995) demonstrated that even at −50° F., acrumb rubber-amended soil bed did not freeze and the hydrogen sulfidereduction remained unaffected.

[0006] Through research conducted at the University of Wisconsin-Madisonsince 1991, crumb rubber has been found to restrict the breakthroughtime of organics dissolved in water by adsorption (Park et al., 1996).Golf course greens and other turf generally require chemicalapplications to maintain turf quality. The current USGA design (USGA,1993) allows rapid movement of water through the soil profile, whichindicates the potential for water-soluble chemicals to leach through thesystem (Cisar and Snyder, 1996; Johnston, 1998) and contaminate groundwater. Therefore, the implementation of crumb rubber into a sub-layer ofgolf course greens could adsorb chemicals dissolved in water, thusprotecting water quality. Furthermore, the physical properties of crumbrubber may be beneficial for golf course greens when the wintertemperature drops below freezing for a long period of time.

[0007] Two roadbeds constructed with shredded tires self-heated andcaught fire in 1996. These sites contained thick sections of tire chipsof 7.9 and 15 m thick. Humphrey et al. (1998) decreased the thickness ofthe tire layer and found that temperatures were decreasing after aslight increase. It was recommended that the thickness of a tire shredlayer be limited to three meters and that relatively large shreds with aminimum of rubber fines be used along with limiting the flow of air andwater into the interior of tire-shred fills (ASTM D6270-98).

[0008] USGA golf course greens are currently constructed based onstringent standards that identify the distinct layer depths and particlesize distribution of construction materials (USGA, 1993). Theconstruction standards outlined by the USGA consist of the top 30 cmlayer (root zone mix) of sand amended with peat and the underlying 10 cmpea gravel layer. Golf course green construction standards establishedby the USGA are designed mainly to improve the playability of golf, notenvironmental impact. Since many greens are built near groundwaterlevels or wetlands, it is vital to consider the mitigation ofenvironmental contamination caused by pesticides and fertilizers used ingolf courses. Furthermore, the public in general demands betterenvironmental protection during golf course construction and operation.

[0009] Sand based root zones, typically 80% or more sand by volume, havebecome the typical method of construction for putting greens and areincreasingly being used for athletic fields and other high traffic turfareas. Sand based root zones are designed for rapid drainage of water toprevent surface puddling and compaction. Specific constructioninstructions have been published (USGA, 1993; Puhalla et al., 1999). Theroot zone is usually amended with peat or other organic materials topromote water and nutrient retention; however, these materials are onlypartially effective and decompose fairly rapidly. In most cases, a layerof gravel (10 cm depth), is used to “perch”, or slow the drainage, aswater will not readily drain from a finer textured soil into a coarsertextured soil until sufficient water (field capacity) has accumulated toallow gravity to overcome the cohesive-adhesive forces of water. Thewater then drains through the gravel layer and into the subsoil. The lowadsorption capacity of sand allows leaching of nutrients and chemicalsinto the ground (Cisar and Snyder, 1996; Johnston, 1998), which maycontaminate groundwater and harm the environment.

[0010] Several patents have been issued related to the use of discardedrubber tires and soil or turf uses. Pluenneke (U.S. Pat. No. 4,166,340)describes a method of using the fibers (cotton, nylon and rayon) frompulverized tires as a lining material in plant pots to prevent soilloss. Tomarin et al. (U.S. Pat. No. 4,396,653) describes the applicationof crumb rubber topdressing into synthetic fiber playing surfaces,designed to keep the fibers upright in order to simulate a natural grasssurface, and to provide resiliency to the field surface. Malmgren et al.(U.S. Pat. No. 5,014,462) described a process of amending native soilroot zones with shredded rubber prior to turf establishment to increasesoil porosity and minimize compaction. The rubber was not added in auniform layer, but rather mixed between 10-30% by volume into the top7.6 to 15.2 cm of soil in order to simulate the drainage and compactionproperties of sand based root zones by increasing the amount ofmacropores. The invention also described use of the rubber-soil mixtureas a base for sod production. The invention claimed improved water andfertilizer use efficiency because turf roots could grow better in themore porous root zone. Rogers et al. (U.S. Pat. No. 5,622,002) describeda method of applying a thin layer (0.25 to 1.9 cm) of crumb rubbertopdressing to the surface of natural grass. The method was designed toimprove the color and growth of the turfgrass by a) protecting theturfgrass crowns (meristems; buds) and b) increasing the temperature ofthe turf surface.

[0011] Herd et al. (U.S. Pat. No. 5,823,711) described a method ofconstructing a “water drainage and collection system ” on golf coursefairways to channel water into a holding area. The channel was to beplaced below the surface of the turf, lined with an impervious barrierthen filled with scrap tires. The tires would ideally be whole tirestied into a bale to allow rapid water drainage by forming apseudo-pipeline. The claim was made that fertilizer and pesticide runoffcould be prevented because water would be effectively channeled into areservoir. The collected water could then be pumped from the reservoirand recycled for golf course irrigation.

[0012] Our claims are unique because our aim is not to channel water,but to adsorb and passively remove fertilizer and pesticide moleculesfrom water as it percolates through the soil. The increased rubbersurface area and uniform layer of crumb rubber in our invention providesa critical mass and surface exchange sites to adsorb .nutrients andchemicals from drainage water before it reaches groundwater. Noimpervious barriers are used in our system to block the downward(gravitational) flow of water. This is important as water, when drawnfrom an aquifer or surface water, needs to be returned to the site so asto “recharge” the system. Ideally, the returned water is notcontaminated with environmentally harmful pollutants. The uniform layerof crumb rubber, 10 cm depth, may perch the water table as per USGAspecifications for putting green construction. The layer may alsogenerate sufficient subsurface heat to promote turf foliar and rootgrowth longer into the autumn/winter than would otherwise occur andpromote earlier growth in the spring. Extending the growing season byaiding turf growth further into the autumn and promoting it earlier inthe spring are desirable to increase turf cover and aid recovery fromtraffic resulting from late or early season play.

[0013] It is an object of this invention to disclose methods of usingwaste rubber materials such as scrap vehicle tires as a constructionmaterial for turf areas such as golf courses and athletic fields. Thismethod is also extended to removing contaminants from water as itpercolates through soils or before entering into detention ponds orwater bodies.

[0014] It is a further object of this invention to use waste rubbermaterials as a lightweight backfill material for construction of turfareas such as golf courses and athletic fields in wetlands and softgrounds.

[0015] An additional object of this invention is to lengthen the growingseason by adding heat in the fall and early spring and retaining heatduring the winter due to the insulating effect of the underground layerof waste rubber materials.

[0016] The last but not only object of this invention is to use wasterubber materials as a supporting layer for athletic fields to provideshock absorption and uniform rebounding characteristics.

SUMMARY OF INVENTION

[0017] The method of this invention pertains to the use of waste rubbermaterials for construction of turf areas such as golf courses andathletic fields to use the following properties of waste rubbermaterials: capability of adsorbing contaminants, insulation, alightweight construction backfill material, and shock absorption. Wasterubber materials are used in lieu of or in addition to a pea graveldrainage layer underneath the root zone of turf areas such as golfcourse greens and athletic fields. This method will allow for thecapture of pesticides and fertilizers applied to turf, thereby reducingpotential groundwater contamination; the early thawing in spring due toinsulation effect by waste rubber materials and thus potential earlyspring growth of turf; and the construction of turf areas in wetlands orsoft grounds. This method also includes the construction of drainagesystems in fairways, tee boxes, putting greens, and other turf areas.Stormwater runoff from turf and other vegetated areas can be filteredwith a layer of waste rubber materials to remove contaminants andparticulates before entering into detention ponds or discharging intosewers due to the adsorption and filtration of contaminants by wasterubber materials.

[0018] The first application of this invention is the replacement of oraddition to the pea gravel layer specified in the USGA greenconstruction standards or other turf areas with waste rubber materials.This will result in mitigation of potential groundwater contamination bypesticides and fertilizers and longer growth period of turf.

[0019] The second application of this invention is the use of wasterubber materials as a backfill material for drainage systems constructedfor turf areas such as golf courses and athletic fields.

[0020] The third application of this invention is the use of wasterubber materials as a lightweight backfill material for constructingturf areas such as golf courses or athletic fields in wetlands and softgrounds.

[0021] The fourth application of this invention is the use of wasterubber materials as a filter medium for removing contaminants in runoffsfrom turf or vegetated areas before entering into detention ponds orwaterbodies.

[0022] The last application of this invention is the use of waste rubbermaterials as a supporting layer for athletic fields to provide shockabsorbing potential and uniform rebounding characteristics.

[0023] The use of waste rubber materials for the construction of golfcourses and athletic fields has the following advantages:

[0024] (1) Adsorption of contaminants

[0025] (2) Insulation

[0026] (3) Lightweight

[0027] (4) Shock absorbing property

[0028] (5) Potentially lower cost

[0029] (6) Environmentally sustainable technology.

BRIEF DESCRIPTION OF DRAWINGS

[0030] The configurations of the present invention are revealed in thefollowing drawings.

[0031]FIGS. 1a, b, c, and d are 3-dimensional views of a golf coursegreen or athletic field utilizing waste rubber for the materialproperties of adsorption of contaminants, lightweight, and insulation.

[0032]FIG. 2 is a 3-dimensional view of a filtering apparatus that willcontain waste rubber as a filter medium.

[0033]FIG. 3 is a 3-dimensional view of an athletic field utilizingwaste rubber for the material properties of shock absorption andresiliency.

DETAILED DESCRIPTION

[0034] It is disclosed that when waste rubber materials are used as adrainage layer in turf areas such as golf courses and athletic fields,the quality of turf grass is improved due to the insulation property ofwaste rubber materials, and the potential for groundwater contaminationis significantly reduced due to the adsorption of contaminants such asnutrients and pesticides by waste rubber materials. When the inventionis applied, it is possible to construct environmentally friendly andsustainable man-made recreational areas even in environmentallysensitive areas.

[0035] The first example application of this invention is thereplacement of or addition to the pea gravel layer specified in the USGAgreen construction standards or other turf areas with waste rubbermaterials. This will result in the mitigation of potential groundwatercontamination by pesticides and fertilizers and a longer growth periodof turf. FIGS. 1a, b, c, and d show 3-dimensional views of a turf areathat requires a drainage layer and utilizes waste rubber such as a golfcourse green or athletic field of the present invention. The system istypically comprised of a root zone layer 1, optional intermediate layer2, drainage layer 3, drainage trench 4, perforated drain tile 5, and asuitable subsoil foundation 6. The root zone 1 consists of sand amendedwith peat. The optional intermediate layer 2 is coarser sand (a) orwaste rubber (c, d) that is recommended mainly to increase the bridgingfactor between the root zone layer 1 and drainage layer 3. The drainagelayer 3 and drainage trench 4 are pea gravel (a, c) or waste rubber (b,d). All material size specifications as well as the determination of theneed for an intermediate layer are based on the particle size andgradation specifications provided by the USGA for golf course greenconstruction (USGA, 1993).

[0036] The second application of this invention is the use of wasterubber materials as a backfill material for drainage systems constructedfor turf areas such as golf courses and athletic fields.

[0037] The third application of this invention is the use of wasterubber materials as a lightweight backfill material for constructingturf areas such as golf courses or athletic fields in wetlands and softgrounds.

[0038] The fourth application of this invention is the use of wasterubber materials as a filter medium for removing contaminants in runoffsfrom turf or vegetated areas before entering into detention ponds,wetlands, or water bodies. The filtration system should be designed tohave a contact time from 30 seconds to 30 minutes depending on type andconcentration of contaminants to be removed. The filtration system shallbe operated in an upflow or downflow mode with or without a layer ofsand below the waste rubber material layer. FIG. 2 shows a 3-dimensionalview of a mechanism for containing waste rubber materials while runoffis passed through the system of the present invention. The containmentdevice is typically made of a wire mesh material 1, top access lid forwaste rubber installation 2, and an internal wire mesh wall 3 foradditional structural stability. The mesh hole, waste rubber, andoverall system sizing are dependent on the expected influent flow rateand desired effluent flow rate.

[0039] The last application of this invention is the use of waste rubbermaterials as a supporting layer for athletic fields to provide shockabsorbing potential and uniform rebounding characteristics. FIG. 3 showsa 3-dimensional view of an athletic field that utilizes waste rubber asa supporting layer. The system is comprised of a 2.5 to 15 cm layer ofwaste rubber 2 located within the top 6 inches from the turf surface 1.The waste rubber layer is partitioned 3 to increase stability within thewaste rubber zone. Layers 7 and 2 can be constructed on a variety ofacceptable foundations 4 such as soil or concrete. The partitions 3 canbe constructed out of a variety of materials with selection based onfactors such as material cost, availability, installation, andresistance to environmental stresses.

[0040] The size of waste rubber materials claimed in this invention forthe replacement of or addition to the pea gravel drainage layer rangesfrom 1 to 12 mm. The size of waste rubber materials for other claims isnot an important factor; thus, the size should be determined based onavailability, workability, constructability, and performance factors. Itis also possible to use tire chips without further refinement with thesize range of 0.25 to 10 cm in the case where there is no need for finersize materials for construction.

[0041] The waste rubber materials claimed in this invention includesscrap vehicle tires, industrial and automobile belts, rubber wastesgenerated from manufacturing of shoes, baby bottle nipples, gaskets, andother products, all of which are free from external contaminants.

[0042] Turf is natural grass, artificial playing surfaces, or variouscombinations of the two.

[0043] Ground rubber is a refined waste rubber material where steelwires, textile cords, and/or other materials except rubber are removed.Chipped waste rubber does not go through any separation besides sizereduction and thus contains steel wires, textile cords, and othermaterials.

What is claimed is:
 1. Use of waste rubber materials for turf areas inwhich the pea gravel drainage layer described in the United States GolfAssociation green or other specifications is replaced or appended bywaste rubber materials for the following properties: (a)adsorption ofcontaminants such as fertilizers and pesticides; (b)control oftemperature of green or other turf areas using the insulation propertyof waste rubber materials; (c)lightweight characteristics of wasterubber materials to apply to construction of turf areas in wetlands orsoft soil foundations.
 2. A method as set forth in claim 1 wherein wasterubber materials are used as a backfill material for turf areas such asgolf courses and athletic fields.
 3. A method as set forth in claim 1wherein waste rubber materials are used in drainage systems for tee boxand sand trap construction in which the gravel applications are replacedby waste rubber materials.
 4. A method as set forth in claim 1 whereinwaste rubber materials have sizes from 1 to 12 mm for ground rubbermaterials and from 0.1 to 10 cm for chipped waste rubber materialswithout further refinement.
 5. Use of waste rubber materials as afiltration system before entering into a detention pond, a wetland, orother waterbody for adsorption and filtration of contaminants as a partof the pollution control system. The contact time in the filtrationsystem should vary from 30 seconds to 30 minutes depending on type andconcentration of contaminants to be removed.
 6. Use of waste rubbermaterials as a 2.5 to 15 cm layer located within the top 20 cmunderneath athletic field turf surfaces to provide resiliency and shockabsorption.